node/test/parallel/test-cluster-setup-master.js

'use strict';
require('../common');
const assert = require('assert');
const cluster = require('cluster');

if (cluster.isWorker) {

  // Just keep the worker alive
  process.send(process.argv[2]);

} else if (cluster.isMaster) {

  const checks = {
    args: false,
    setupEvent: false,
    settingsObject: false
  };

  const totalWorkers = 2;
  let onlineWorkers = 0;

  // Setup master
  cluster.setupMaster({
    args: ['custom argument'],
    silent: true
  });

  cluster.once('setup', function() {
    checks.setupEvent = true;

    const settings = cluster.settings;
    if (settings &&
        settings.args && settings.args[0] === 'custom argument' &&
        settings.silent === true &&
        settings.exec === process.argv[1]) {
      checks.settingsObject = true;
    }
  });

  let correctIn = 0;

  cluster.on('online', function lisenter(worker) {

    onlineWorkers++;

    worker.once('message', function(data) {
      correctIn += (data === 'custom argument' ? 1 : 0);
      if (correctIn === totalWorkers) {
        checks.args = true;
      }
      worker.kill();
    });

    // All workers are online
    if (onlineWorkers === totalWorkers) {
      checks.workers = true;
    }
  });

  // Start all workers
  cluster.fork();
  cluster.fork();

  // Check all values
  process.once('exit', function() {
    assert.ok(checks.workers, 'Not all workers went online');
    assert.ok(checks.args, 'The arguments was noy send to the worker');
    assert.ok(checks.setupEvent, 'The setup event was never emitted');
    const m = 'The settingsObject do not have correct properties';
    assert.ok(checks.settingsObject, m);
  });

}